Effect of original grain size on microstructure and properties of extruded Mg-2Zn-0.2Mn biomedical alloy

ABSTRACT

Magnesium is a biocompatible and biodegradable metal, which has attracted much interest in biomedical engineering. Cast magnesium alloy shows the low strength and plasticity at ambient temperature. Microstructure, mechanical properties and degradation properties of the extrusion pressed magnesium alloy have been investigated for biomedical application in detail by optical microscopes, mechanical properties testing and corrosion testing. The magnesium alloy ingots were gained by different cooling rate. Then the ingots were extrude into bar at the same processing condition. The results show that the cooling rate of cast ingot is important factors that affect the properties of Mg alloy by dynamic recrystallisation extruding. The cooling rate of cast ingot has been successfully applied to control the microstructure, mechanical and degradation properties of the Mg alloy. Optical microscopy observation has indicated that the grain size of the dynamic recrystallisation extruding has been significantly decreased from fast cooling cast magnesium ingot, which has mainly contributed to the high tensile strength and good elongation. Fasting cooling rate of cast ingot and dynamic recrystallisation extruding has provided moderate corrosion resistance, which has opened a new window for materials design, especially for biomedical.

KEYWORDS:

• Biomedical Magnesium alloy
• Ingot cooling rate
• Microstructure
• Mechanical property
• Corrosion Property

Acknowledgement

This work was financially supported by NSFC 81271701.